September 20, 2021 – The Cobra dog worked hard at Miami International Airport, sniffing masks donated by American Airlines employees as they made their way through a security checkpoint. If she identifies a specific scent, she will let her master know just by sitting down. When this good girl sits down, it means Cobra has detected an olfactory signal from the coronavirus, the virus that causes COVID-19.
Cobra, a Belgian Malinois, is one of two dogs – his partner is One Betta, a Dutch Shepherd – working at this checkpoint at Miami International. They are part of a pilot program with the Global Forensic and Justice Center at Florida International University, using detection dogs as a rapid test for people with COVID-19.
Their detection rate is high, at over 98%, and the program is so successful that it is extended for one month at the airport.
If these two dogs continue to accurately detect COVID-19, they and other dogs with similar training could be deployed to other locations with lots of people coming and going at once, including other airports or even schools. In fact, COVID sniffer dogs are already in use in some college classrooms.
But building up a large brigade of live animals as disease detectors involves thorny issues, including knowing where animals retire once their careers are over.
“When COVID first appeared, we said let’s see if we can train these two dogs on the virus or the smell of COVID-19,” says Kenneth Furton, PhD, professor of chemistry and biochemistry, marshal and vice -Executive chairman at Florida International University.
His team had completed a study with what he calls “medical detector dogs,” animals that might be able to detect the scent of a person having a seizure. This led them to see how well animals could detect other types of disorders.
Training a dog to smell specific scents starts with making him understand the task in general. Furton says animals are first trained to understand that their job is to detect one scent among others. Once dogs figure this out, they can be trained on just about any specific scent.
In fact, in addition to detecting seizures, dogs could have identified diabetes and even some cancers, such as ovarian cancer.
Furton says he is not aware of any previous use of dogs to screen for infectious diseases. This may simply be because nothing has struck with the global ferocity of COVID lately, causing humans to turn to their best friends for help.
Cobra and One Betta have started learning to identify the presence of bay leaf blight, a fungus that attacks and kills avocado trees, costing Florida growers millions. With this expertise under their collars, both dogs only need a few weeks to familiarize themselves with the other scents attributed to them.
Train dogs safely
To train Cobra and One Betta on the smells of COVID-19, Furton’s team first acquired mask samples from people hospitalized with COVID and from people who did not have the disease. In battling viruses, people produce certain chemicals that they breathe out every time they breathe. When Furton and his colleagues compared the expired components trapped in the masks, they found differences between the masks of people with COVID and those without.
After confirming that expirations may be specific to COVID, the research team trained four dogs – Cobra, One Betta, Hubble and Max – to detect masks for people with COVID from an assortment of mask choices. Before this step, however, the researchers made sure that all traces of the active virus were destroyed by ultraviolet light so that the dogs did not become infected.
Whenever the dogs accurately selected a mask from a COVID patient, their reward was access to a favorite toy: a red chew ball. While all four dogs performed very well, yes they did, Cobra and One Betta showed the most accuracy, outperforming their training colleagues. Based on their training scores, Cobra placed first, with an accuracy of 99.45%. Despite its name, says Furton, One Betta was “no better”, ranking second at 98.1%, which is still pretty high.
Both dogs are good at their screening duties at the airport. If one of them sits after sniffing a mask at the checkpoint, the next step is to test the owner of the mask.
From Aug. 23 to Sept. 8, the two dogs screened 1,093 people over 8 working days, alerting to a single case, according to Greg Chin, communications director for the Miami-Dade Department of Aviation. This person had tested positive for COVID 2 weeks earlier and was returning to work after quarantine, and his rapid test after the dog alert was negative.
Furton says there are reports of dogs also alerting before tests can show a positive result, suggesting that the detection of dogs’ odors may be more accurate. They hope to expand their study to see how narrow the window for dog-based detection is.
So far, the detector dogs are doing so well that the program has been extended for another 30 days, Chin said.
As promising as it sounds, there are logistical and ethical issues with using dogs for screening. Training a canine army to deploy to high-volume detection points means that once the job is done, many dogs will need a safe place to retire. Plus, initial training takes several months, says Furton, while if a device were developed for screening, manufacturing could likely be ramped up quickly to meet demand.
However, dogs may not need to retire right away.
“We are considering that they could be redeployed to another type of detection for another infectious disease” if the need arises, says Furton. But at the end of the day, when working with dogs, he says, there is “a moral bond that you don’t have to deal with with the help of instruments.”
While the pilot screening at Miami International is the first test at the airport, dogs have done this work in other locations as well, including a state emergency operations center in Florida and some wards. college class, says Furton.